Comparison of three types of adhesives in attaching coral transplants to clam shell substrates

• 1. Nubbins from 12 coral species were transplanted onto dead giant clam shells at three sites in a lagoon near Bolinao, north‐western Philippines. Transplants were attached using three types of adhesives: cyanoacrylate glue (SG), epoxy putty (EP) and marine epoxy (ME) and were monitored over five months for detachment, in situ mortality and natural self‐attachment by tissue growth.
• 2. Corals attached with SG showed a significantly higher rate of detachment (logrank test) than those attached with either EP or ME (P<0.001 in each case). Also, those attached with EP showed a higher rate of detachment than corals attached with ME (logrank=6.46, P<0.05).
• 3. ANOVA (P>0.05) and survival analysis (logrank=2.85, P>0.05) showed no among‐adhesives differences in in situ mortality. Among the species used, Porites cylindrica, Pavona frondifera, Heliopora coerulea and Porites rus had the highest survivorship with 82%, 80%, 76% and 73%, respectively, of nubbins alive at the end of the experiment and also displayed the highest cumulative rates of self‐attachment. Species with the lowest survival rates included Acropora muricata and four pocilloporids.
• 4. Although there was no significant difference in the number of self‐attaching transplants among the adhesives, corals transplanted using ME and EP self‐attached earlier than those transplanted using SG (logrank=11.19, P<0.01).
• 5. Results from this study highlight the importance of selecting the appropriate means of attaching corals to substrates and carefully considering species‐specific traits of candidate corals for transplantation.

Copyright © 2008 John Wiley & Sons, Ltd.     

Cage‐pond integration of African catfish (Clarias gariepinus) and Nile tilapia (Oreochromis niloticus) with carps

Cage‐pond integration system is a new model for enhancing productivity of pond aquaculture system. A field trial was conducted using African catfish (Clarias gariepinus) and Nile tilapia (Oreochromis niloticus) in cages and carps in earthen ponds. There were four treatments replicated five times: (1) carps in ponds without cage, (2) tilapia at 30 fish m^?3 in cage and carps in open pond, (3) catfish at 100 fish m^?3 in cage and carps in open pond, (4) tilapia and catfish at 30 and 100 fish m^?3, respectively, in separate cages and carps in open pond. The carps were stocked at 1 fish m^?2. The cage occupied about 3% of the pond area. The caged tilapia and catfish were fed and the control ponds were fertilized. Results showed that the combined extrapolated net yield was significantly higher (P < 0.05) in the catfish, tilapia and carps integration system (9.4 ± 1.6 t ha^?1 year^?1) than in the carp polyculture (3.3 ± 0.7 t ha^?1 year^?1). The net return from the tilapia and carps (6860 US$ ha^?1 year^?1) and catfish, tilapia and carps integration systems (6668 US$ ha^?1 year^?1) was significantly higher than in the carp polyculture (1709 US$ ha^?1 year^?1) (P < 0.05). This experiment demonstrated that the cage‐pond integration of African catfish and Nile tilapia with carps is the best technology to increase production; whereas integration of tilapia and carp for profitability.     

Electrical stunning followed by decapitation or chilling of African catfish (Clarias gariepinus): assessment of behavioural and neural parameters and product quality

The objective of this study was to assess neural and behavioural responses in farmed African catfish (Clarias gariepinus) upon electrical stunning in combination with decapitation or chilling. To assess the possibility of scaling up one or both experimental methods, two trials were performed in an experimental setting. The product quality of the collected samples was compared with the currently applied industrial method: live chilling. After electrical stunning in combination with decapitation, the fish showed spikes alternated with theta and delta waves on the EEG, followed by minimal brain activity after 20±10 s. The same traces on the EEGs were observed after electrical stunning in combination with chilling. Here, minimal brain activity occurred after 22±11 s. Within a confidence level of 95%, the percentage of African catfish that was effectively stunned after administration of an electrical current of 1.5 A dm⁻², 300 V (50 Hz a.c.), followed by decapitation or chilling was above 91%. The analysis yield and evolution of liquid loss showed significant (P<0.05) differences among the batches, which could be explained by the stunning method used. The course values of the pH in the different batches were significantly (P<0.05) dependent on the stunning method, sex and location (visceral or skin side). It is concluded that African catfish can be stunned effectively using electrical stunning in a water tank, followed by decapitation or chilling in ice. Dutch commercial processors prefer to combine electrical stunning with chilling in flake ice in a rotating tumbler, as the outer slime layer is then removed, which facilitates further processing.     

Comparison of larval performance between Thai and Vietnamese freshwater giant prawn, Macrobrachium rosenbergii (de Man): a preliminary study

This study compared the performance of larvae of giant freshwater prawn (Macrobrachium rosenbergii) from Thailand and Vietnam. Thai broods were collected from a farm and Vietnamese broods were collected from a river. Larvae from these two sources were raised in identical environments, and their rates of development and survival as well as their ability to withstand environmental stresses were assessed. The first postlarval stage was observed in both strains on day 22. All larvae (100%) from Thai broods completed metamorphosis by day 36, but only 89% of the Vietnam strain completed metamorphosis by day 45. The stages of development were more uniform in larvae from the Thai stock than the Vietnamese stock. Survival differences were observed within the first week (92% in the Thai group vs. 55% in the Vietnamese group). These differences were most pronounced beginning in week 5 (52% and 16% respectively) and week 7 (33% and 2% respectively). No clear difference was found in brood size and fecundity between the two groups. No difference in survival was observed between the two groups of larvae challenged with salinity, oxygen or formalin. Differential development rates of larvae in the same batch would naturally create conditions favourable for cannibalism and impaired ability to capture food. The earlier and more uniform rate of development, and subsequent higher rate of survival of Thai stock compared with the Vietnamese wild stock is suggested to be due to inadvertent selection in the domesticated stock.     

诱捕井防治森林鼠害的试验

利用塑料瓶投放诱饵设置诱捕井的办法防治森林害鼠 ,1hm2 设 5 0个诱捕井 (10m× 2 0m ) ,2 4h诱捕率 90 % ,防治效果 90 6 %。     

大鲵虹彩病毒主要衣壳蛋白的原核表达及多克隆抗体制备

根据大鲵虹彩病毒(Chinese giant salamander iridovirus,GSIV)主要衣壳蛋白(Major Capsid Protein,MCP)基因设计引物,PCR扩增得到MCP基因编码框全长序列1 392 bp,将其克隆到原核表达载体p ET-32a中,构建了重组原核表达载体p ET-32a-MCP,并在大肠杆菌BL21中得到了表达,融合表达的重组蛋白分子量约为70 ku,与预期大小一致,主要以包涵体的形式存在。对IPTG浓度,诱导温度等诱导表达条件进行优化,确定0.5 mmol/L的IPTG于37℃的条件下诱导6 h重组蛋白的表达量最佳。纯化GSIVMCP重组蛋白免疫新西兰大白兔,制备了GSIV-MCP多克隆抗体,ELISA检测抗体效价大于1∶50 000。Western blot检测显示该抗体可以特异性识别重组蛋白。间接荧光免疫结果表明,该多克隆抗体可与由GSIV感染引起细胞病变的EPC细胞(GICB)发生特异性的结合。研究为建立GSIV免疫诊断方法以及为研究GSIV MCP基因编码蛋白的功能奠定了前期基础。     

古巴非洲猪瘟根除的经验与借鉴

1971年非洲猪瘟首次传入古巴并于当年根除,1980年再次传入并在一年内又被根除。古巴能快速根除非洲猪瘟,主要与防控专业委员会的及时成立,协作机制的快速建立;全面扑杀措施的快速实施,健康猪产品的合理利用;民间团队的积极参与以及政府财政的大力支持密切相关。古巴的根除经验,可为我国非洲猪瘟的防控提供参考。     

Evaluation of auditory evoked potentials to predict depth of anaesthesia during fentanyl/fluanisone−midazolam anaesthesia in rats

Objectives To assess a method for monitoring depth of anaesthesia using components of middle latency auditory evoked potential (AEP) waveforms during anaesthesia with fentanyl/fluanisone and midazolam. Study design Prospective observational study. Animals Five female Wistar rats weighing between 210 and 250 g. Methods Implanted electrodes were used to record AEPs in animals receiving five doses of anaesthetic. Recordings were made at 5 minutes post‐injection (deep anaesthesia; no pedal withdrawal response, PWR) and then at 25 minutes (light anaesthesia; strong PWR). Responses showed five characteristic peaks occurring at 11, 14, 23, 42 and 68 ms that were measured for latency of occurrence and peak amplitude. Results Auditory evoked potential peaks P14, N23 and P42 were increased significantly in latency with successive anaesthetic injections [avg. F(1,4) = 12.53, p < 0.001; avg. F(1,4) = 10.6, p < 0.001; avg. F(1,4) = 3.9, p = 0.02, respectively]. Peak N23 showed a significant reduction in latency during the 20 minute recovery period following both the first and second anaesthetic injections (t(3) = 7.52, p = 0.005; t(4) = 5.17, p = 0.007, respectively). Peak P42 occurred significantly earlier 20 minutes following the second anaesthetic injection (t(4) = 4.75, p = 0.009). The mean overall depth of anaesthesia assessed using PWR scores was significantly correlated with the mean latency of peak N23, such that as the strength of PWR increased, N23 occurred significantly earlier (r = ?0.99, p = 0.01). The amplitude difference between peaks N23 and P42 increased after the second and third drug administrations [avg. F(1,4) = 10.65, p = 0.031 and avg. F(1,4) = 11.24, p = 0.028, respectively]. Conclusion The characteristics of these peaks, and in particular latency of peak N23, may provide a useful tool for assessing depth of anaesthesia produced by this, and possibly other anaesthetic agents.     

基于鼹鼠多趾结构特征的仿生切土刀片设计与试验

为降低土壤耕作阻力,分析了鼹鼠前肢手掌的多趾组合结构特征,得到鼹鼠多趾组合结构是一种多窄齿组合结构,且相邻齿间间距可调整,最终确定了多趾组合结构的数学模型。基于该模型,设计了具有仿生结构特征的切土刀片。通过土槽试验,采用四因素三水平的二次正交回归试验方法,分析仿生结构元素m和n、土壤含水率和切土倾角对水平阻力的影响,得到土壤含水率和切土倾角对水平阻力的影响更显著,最优仿生结构元素m为5、n为1.75。通过比较传统和仿生刀片在切土倾角10°~90°和土壤含水率10%~30%下的水平阻力,得到仿生几何结构对刀片切土的临界倾角无显著影响,但土壤含水率对其有显著影响：当土壤含水率为10%和20%时,临界倾角均为30°左右;当土壤含水率为30%时,临界倾角均在40°~50°之间。然而,仿生几何结构对刀片所受的水平阻力有显著影响,在相同的土壤含水率下,仿生刀片的水平阻力总小于传统刀片的水平阻力：当土壤含水率为10%、20%、30%时,仿生刀片的水平阻力分别减小11.48%~39.16%、17.81%~28.00%和11.19%~33.26%。此外,水平阻力的变化与土壤内聚力具有极大的相关性,研究表明土壤含水率为10%~20%时,仿生刀片具有更好的切土性能。     

Vitamin C enhanced myocardial differentiation of dedifferentiated fat cells

AIM: In order to observe the myocardial differentiation capacity of the dedifferentiated fat (DFAT) cells treated with vitamin C in vitro. METHODS: DFAT cells were dedifferentiated from the mature rat adipocytes with ceiling adherent culture. The DFAT cells of passage 3 were used in the study. Vitamin C and/or neonatal rat heart tissue lysate were added into the culture medium to induce myocardial differentiation for 3 weeks. The cell morphology was observed under microscope. The myocardial-specific markers, such as cTnT, GATA-4 and NKx2.5, were examined by the methods of immunofluorescence, PCR and Western blot. RESULTS: Mature rat adipocytes dedifferentiated into fibroblast-like DFAT cells after ceiling adherent culture. The DFAT cells spontaneously differentiated into cardiomyocyte-like cells under normal culture condition with a low incidence. After treated with neonatal rat heart cell lysate, the DFAT cells became cardiomyocyte-like cells that had bigger size, longer shape and myotubule-structure. The expression of cTnT, GATA-4 and NKx2.5 was remarkably increased at both mRNA and protein levels as compared with the normal cultured DFAT cells. The expression of cTnT, GATA-4 and NKx2.5 was further increased in DFAT cells after treating with vitamin C. No spontaneous beating cell was observed. CONCLUSION: Vitamin C enhances the differentiation of DFAT cells into cardiomyocyte-like cells.